Drilling device with means to indicate resistance to rotation



Oct. 10, 1967 o. MEYER 3,345,299

DRILLING DEVICE WITH MEANS TO INDICATE RESISTANCE TO ROTATION Filed Nov.18, 1964 H6. 3 F/G.4

INVHW'OP O TTO I"! E /E R United States Patent 3,346,299 DRILLING DEVICEWITH MEANS T0 INDI- CATE RESISTANCE T0 ROTATION Otto Meyer, Mulheim(Ruhr), Germany, assignor to Demag Alrtiengesellschaft, Duisburg,Germany Filed Nov. 18, 1964, Ser. No. 412,069 Claims priority,application Germany, Nov. 20, 1963,

42,982 Claims. (Cl. 299-1) This invention relates in general to adrilling apparatus and in particular to a new and useful device fordrilling particularly tunnels, drifts or other ground or earthexcavations employing means for visually indicating the workingresistance of the drilling tools for the purpose of controlling thedrilling operation.

When driving tunnels, drifts and even in the drilling of vertical oroblique drilling excavations in the ground or the rock by use of adrilling device having a plurality of tools such as drills, cutters,blades, shovels and the like, it is usual that some of the tools willencounter areas of increased resistance due to a very hard formationswhich will make the affected tools blunt in a short time or even destroythem completely. For example, when rocks or metallic foreign bodies arefound in the ground, the rocks may contain elements of particularhardness and particular tools of the overall drilling apparatus maystrike on such hard elements which may even include petrification oriron girders which have remained from previous drillings. In someinstances it is even possible that the drilling operation may cause thestriking of an undetected bomb which further increases the danger of thedrilling operation.

In the devices presently known for drilling large openings such astunnels, it is difficult, if not impossible for the operator todetermine when the drilling apparatus will encounter areas of increasedresistance because the operators view is concealed almost entirely bythe rotary tool holder. In some cases it is necessary to interposepressure chambers, especially where water breaks-in are anticipated.Such pressure chambers are only accessible through special gates oropenings and thus it is impossible to observe the forward ground or rockto be drilled. When using prior art drills it was thus very likely thatthese unexpected resistance areas would be encountered and this wouldresult in a long term and annoying stoppage with the resultant expensein respect to the loss of time and the requirements of the replacementof tools.

The present invention deals with a device by which the areas ofincreased resistance can be rapidly indicated, recognized and located,so that the work can be stopped before the tools have been blunted ordestroyed or other dangers appear. A particularly hard foreign body canbe drilled out by special tools or pealed out (i.e. removed by firstremoving the surrounding substances to release it) or crushed. After theforeign body is thus pulled away, the work can be resumed Withoutreplacing or resetting the cutting tools.

In accordance with a preferred arrangement of the invention, the workingresistance encountered by each of the tools or by selected ones of thetools which will be indicated by the cutting pressure encountered, thedrilling pressure, the torque in rotating a rotary drill, the currentintensity for driving the rotary drill etc. is measured, eithermechanically, hydraulically, electrically, or magnetically and eithercontinuously or at fixed intervals and the measuring result istransmitted to indicating means for visually indicating variations inthese working resistance measuring elements which are encountered by theselected drills. In a preferred arrangement the results are transmittedto a revolving synchronous device which in the simplest form may includelight producers or 'ice each bulb. With such an apparatus it is possibleto have a ready indication of the areas of specific resistance on thefront of the tunnel being driven made visible on the synchronous deviceby increased or reduced light intensity. The arrangement is particularlydesirable for those tools which are driven at particularly high speeds.

When the overall tool which is boring the tunnel is moved at a lowerspeed the synchronous device should advantageously include fluorescentscreen having a persistence effect so that the light which is emittedfrom the bulbs which represent the particular drills will remain on thescreen for a longer period of time. This may, for example, comprise aluminous strip or luminous spot (light and dark spots) which areobtained and can be recognized according to type and intensity and bymeans of which the location, the extent and the hardness of the foreignbody can be measured or at least estimated.

In a preferred arrangement the synchronous device advantageouslyincludes a rotatable disc having a number of bulb elements,corresponding to the number of drills being employed by the rotarydrilling tool, which are mounted on the synchronous device or disc forrotation at the same speed as the work holder of the drill. For toolsthat move at a lower speed it is advisable to use a fluorescent screenso that the light emitted from the synchronous device remains for alonger period of time. The synchronous device or disc is put intorotation mechanically by the revolving tool disc or by its drive or bymeans of an electric sychronizing drive. In some instances it ispreferred that the rotary synchronizing element be a disc of the samenature as the tool holder in which each of the rotary drills aremounted. Instead of incandescent bulbs, a fluorescent screen can be usedor a similarly designed braun tube or other known optical means.

In some instances it is desirable to provide means on each of the toolssuch as scanning elements which measure the resistance, the feed orother suitable quantities, to increase the number of light producers,and thus the number of light points and provide a sufficient picture ofthe extent and location of the area of increased resistance, even with asmaller number of tools. The synchronous device, such as a rotary dischaving the light bulbs corresponding to the individual tools mounted ona rotary tool holder, is preferably arranged on a control stand behind afluorescent screen which may be easily observed by the operator. Theoverall effect of this device advantageously is such as to give a visuallight indication of the appearance of a heavy resistance area which isbeing encountered by the rotary drill.

Accordingly it is an object of the invention to provide a drillingapparatus which includes a rotary holder having a plurality of rotatabledrills projecting outwardly from the holder at radially spaced locationsand with indicating means connected to selected ones of the drills andresponsive to a change in the resistance encountered by such drills inthe drilling operation to vary an indication such as a light which maybe easily viewed by the operator of a drill.

A further object of the invention is to provide a tunnel drilling devicecomprising a rotary drilling tool including a rotary plate or dischaving a plurality of rotary drilling elements thereon arranged in aplurality of radially spaced locations, with a rotary synchronouselement having visual indicating means thereon such as light bulbsconnected to the rotary drill and rotatable in timed sequence thereto,and including electrical means connected to each of the rotary drillsand to the indicating means to vary the indications in accordance withthe resistance encountered by the drills during the drilling operation.

A further object of the invention is to provide a rotary drilling deviceincluding means for visually indicating the magnitude of the resistancebeing encountered by a plurality of individual drilling elements on ascreen in a position for continuous viewing by an operator.

A further object of the invention is to provide a device for drilling inthe earth which is simple in design, rugged in construction andeconomical to manufacture.

The various features of novelty which characterize the the invention arepointed out With particularity in the claims annexed to and forming apart of this specification. For a better understanding of the invention,its operating advantages and specific objects attained by its use,reference should be had to the accompanying drawings and descriptivematter in which there is illustrated and described a preferredembodiment of the invention.

In the drawings:

FIG. 1 is a side elevational view of a cutting head having millingcutters;

FIG. 2 is a somewhat schematic transverse sectional view of a completeoperational drill constructed in accordance with the invention;

FIG. 3 is a front elevational view of a signal rotor or synchronousdevice; and

FIG. 4 is a front elevational view of the fluorescent or indicatingscreen.

Referring to the drawings in particular, the invention embodied thereincomprises a tunnel drilling apparatus including a rotary tool holder ora disc it which is secured to a rotatable shaft 5 for rotationtherewith. On the disc 1 are arranged in three separate radial rows, aplurality of milling tools or rotary drill elements 2 each having adriving motor 3. The disc or holder 1 is driven by a shaft 5 which inturn is rotated by means of a device such as a motor 4.

In the drilling apparatus indicated there is provided an end plate 6located at an inwardly spaced location from the rotary drill holder 1and defining a pressure chamber 7 therebetween. The pressure chamber 7is maintained under a positive pressure distinct from that in the spacewith the operators seat 12 and it is accessible through a gate formation8 defined in the end plate 6. The rotary holder 1 is also provided witha shovel device 10, which is schematically indicated and which providesmeans for conveying or removing the material which is excavated throughthe end plate 6 in the direction of the arrow 11. The operator of thedrill will normally be positioned inside or inward of the end plate 6and at such location it is impossible to see the resistance which isbeing encountered by each of the drill elements 2.

In accordance with the invention a measuring and signal sequence isprovided to permit the operator to observe any special resistances whichmay be encountered by the operation. The apparatus advantageouslyincludes measuring instruments provided for each of the tools 2 or on apart connected to them, for example, on the drive 3 for the machines, inorder to measure the working resistance which is encountered by eachtool. The working resistance can of course be measured, such as by anincrease in the power required to drive the tools, by direct measurementof the torque acting on the shaft driving the drills, or by ameasurement of the driving power required which may be measured, forexample, by hydraulic, pneumatic or electrical means. Torque indicatorsare known in several models for all of these arrangements.

An example of one means for measuring the resistance exerted by thesolid face shoulder of the tunnel on the individual milling cutters is ameasurement of the current consumption of each of the individual drivingmotors 3 of the milling cutters. Thus, the measuring instrument 15 maycomprise in a simple case a simple ammeter. The indications on theammeters 15 may be transformed as electrical signals to correspondinglyvary the intensity of the light indicators 20 of the synchronizing disc19. In FIG. 2, a multi-cable electrical connection 5a for separatelyconnecting each of the instruments through the collector 17 to theamplifier 22 is shown as extending through the shaft 5.

In accordance with the invention the measuring units 15 are connectedelectrically through connecting lines 16 which extend along the shaft 5and which are connected individually to respective current collectorelements 17 spaced along the shaft. There is provided one currentcollector 17 for each of the rotary drills Z.

From the same shaft 5 is taken a mechanical drive 18 which rotates asynchronous device such as a rotatable disc 19 at a rotational speed inproportion to the rotation of the holder i. The disc 19 is provided witha plurality of light bulbs or electrical indicating means arranged inthree radial rows with a separate indicating means being aligned on thedisc 19 in the same relative location as the tools 2 are aligned on thework holder ii.

The current flowing through the collectors 17 varies in accordance withthe changes in working resistance encountered by the tools 2 and thiscurrent signal is amplified by the amplifier 22 and each amplifiedsignal is connected individually to a respective electrical indicator orbulb 20 corresponding to the particular affected rotary drill tool.Signals may be set, for example, so that the bulbs 23 will light up to abrighter intensity when the resistance encountered by the associatedrotary drill 2 is increased.

The operator will normally sit in the seat indicated 12 in front of afluorescent screen 25 and thus he can recognize by the brightening ofthe bulbs at certain points of their path the position and perhaps alsothe extent of a foreign body having a particularly great cuttingresistance which may be encountered by the drill. When the holder 1 isrevolved at relatively slow speed it is advisable to arrange afluorescent afterglow screen 25 having a persistence effect, forexample, a screen having a phosphorescent coating in front of thesynchronizing disc. In this manner the screen 25 will hold the lighteffect when the bulbs pass by the point of increased resistance untilthey again pass by the same point and the light effect will be widenedsomewhat so that a light spot and dark spot 25a is formed Which informsthe operator rapidly about the position, size and form of the piececausing the resistance. The dark spot 25a represents an area of greaterbrightness on the afterglow screen 25. The light sources 20 arrangedaccording to the cutters 2 of FIG. 1 are mounted on a supporting disc 19(FIG. 3) which rotates in synchronism with the cutter disc 1 and thelight sources light up brighter when the associated drills encounter aregion of higher resistance than those whose associated drills encounternormal resistance. This increased light in a particular area forms anafterglow effect on the screen 25 providing a visual indication of thelocation of the high resistance areas.

Instead of driving the indicator mechanically from the shaft 5 or fromthe drive 4 it is sometimes preferable to provide a separate drive whichmay be operated in synchronism with the disc 1, for exampleelectrically, such as by using a selsyn motor and a selsyn transmitter.It should also be appreciated that there are other electrical indicatorsbesides bulbs and any device which will emit radiation or energyimpulses may be employed on the revolving disc 19.

With slowly rotating tool discs It the light effect can be increased onthe optical device, if necessary. This lighting effect, for example, maybe increased by rotating the device faster than the tool disc.

While a specific embodiment of the invention has been shown anddescribed in detail to illustrate the application of the inventiveprinciples, it will be understood that the invention may be embodiedotherwise without departing from such principles.

What is claimed is:

1. A drilling device comprising a rotary drill holder, means forrotating said drill holder, a plurality of rotary drills mounted forrotation on said drill holder at a plurality of angularly spacedlocations, means to rotate said drills, electrical means connected toeach of said drills transmitting an electrical signal varying inintensity only in proportion to the intensity of the resistance torotation encountered by the associated drill during its rotation asaifected by the substance which it encounters during drilling, andvisual indicating means connected to said electrical means and visuallyindicating the resistance encountered by each drill at each position ofits rotary movement along with rotation of said holder.

2. A drilling device comprising a rotary drill holder, means forrotating said drill holder, a plurality of rotary drills mounted forotation on said drill holder at a plurality of angularly spacedlocations, means to rotate said drills, electrical means connected toeach of said drills transmitting an electrical signal varying inintensity in proportion to the intensity of the resistance to rotationencountered by the associated drill during its rotation as affected bythe substance which it encounters during drilling, and visual indicatingmeans connected to said electrical means and visually indicating theresistance encountered by each drill at each position of its rotarymovement along with rotation of said holder, including a rotary discelement, means for rotating said disc at a speed proportional to thespeed of rotation of said holder and electrical indicators on saidrotary element of a number and a location corresponding to the numberand location of said drills on said holder.

3. A drilling device comprising a rotary drill holder, means forrotating said drill holder, a plurality of rotary drills mounted forrotation on said drill holder at a plurality of angularly spacedlocations, means to rotate said drills, electrical means connected toeach of said drills transmitting an electrical signal varying inintensity in proportion to the intensity of the resistance to rotationencountered by the associated drill during its rotation as affected bythe substance which it encounters during drilling, and visual indicatingmeans connected to said electrical means and visually indicating theresistance encountered by each drill at each position of its rotarymovement along with rotation of said holder, including a rotary discelement, means for rotating said disc at a speed proportional to thespeed of rotation of said holder, electrical indicators on said rotarydisc element of a number and a location corresponding to the number andlocation of said drills on said holder, and a screen disposed adjacentsaid holder in a position to be influenced by the variations ofelectrical indications on said disc for giving a visual indicationthereon.

4. A drilling device according to claim 3 wherein said screen has acharacteristic of retaining light when it is received thereby, saidelectrical indicators on said disc comprising light indicators.

5. A drilling device comprising a rotary drill holder, means forrotating said drill holder, a plurality of rotary drills mounted forrotation of said drill holder at a plurality of angularly spacedlocations, means to rotate said drills, electrical means connected toeach of said drills transmitting an electrical signal varying inintensity in proportion to the intensity of the resistance to rotationencountered by the associated drill during its rotation as effected bythe substance which it encounters during drilling, and visual indicatingmeans connected to said electrical means and visually indicating theresistance encountered by each drill at each position of its rotarymovement along with rotation of said holder, said rotary drill holderhaving three equally spaced radial rows of said drills, said visualindicating means including a rotary disc having lights thereon arrangedin three equally spaced radial rows of lights with each light in a rowcorresponding in position to a respective drill in a row on said holder,and means for rotating said disc at a speed proportional to the speed ofrotation of said holder.

6. A drilling device comprising a rotary drill holder, means forrotating said drill holder, a plurality of rotary drills mounted forrotation on said drill holder at a plurality of angularly spacedlocations, means to rotate said drills, electrical means connected toeach of said drills transmitting an electrical signal varying inintensity only in proportion to the intensity of the resistance torotation encountered by the associated drill during its rotation asaffected by the substance which it encounters during drilling, andvisual indicating means connected to said electrical means and visuallyindicating the resistance encountered by each drill at each position ofits rotary movement along with rotation of said holder, said rotarydrill holder comprising a substantially disc shaped forward wall, an endplate spaced from said forward wall and defining adjacent the end plateand said forward wall a pressure chamber, an operators station outsideof said pressure chamber, said visual indicating means being locatedadjacent said operators station for permitting the operator to visuallyobserve changes in resistance encountered by the drills during thedrilling operation.

7. A drinking device comprising a rotary disc-shaped drill holder, meansfor rotating said drill holder, a plurality of drills rotatably mountedon said holder at a plurality of angularly spaced locations, means torotate said drills including electrical drive means for each of saiddrills, electrical means connected to each drive means of said drillsand responsive to said drive means for transmitting an electrical signalvarying in intensity only in proportion to the intensity of theresistance encountered by the associated drill during its rotation asafiected by the substance which is encountered during drilling, andvisual indicating means connected to said electrical means to indicatevisually variations in resistance encountered by each drill at eachlocation of its movement during rotation of said rotary drill holder.

8. A drilling device comprising a rotary drill holder, means forrotating said drill holder, a plurality of drills rotatably mounted onsaid holder at a plurality of angularly spaced locations, means torotate said drills, electrical means connected to each of said drillstransmitting an electrical signal varying in intensity in proportion tothe intensity of the resistance encountered by the associated drillduring its rotation as affected by the substance which is encounteredduring drilling, visual indicating means connected to said electricalmeans to indicate visually variations in resistance encountered by eachdrill at each location of its movement during rotation of said rotarydrill holder, means to rotate said rotary drill holder, said indicatingmeans including a rotary disc, and means connected between said means torotate said rotary drill holder and said rotary disc to rotate saidrotary disc at a speed in proportion to the speed of rotation of saidholder, said indicating means including a plurality of indicating lightson said disc of a number corresponding in number and location to thedrills on said holder, whereby when said holder and said disc arerotated, the intensity of light on said lights on said disc is a visualindication of resistance being encountered by each of the drills on saidholder.

9. A drilling device comprising a rotary drill holder, a plurality ofrotary drills mounted for rotation on said drill holder at a pluralityof angularly spaced locations, means to rotate said drills, electricalmeans connected to each of said drills transmitting an electrical signalvarying in intensity only in proportion to the intensity of theresistance to rotation encountered by the associated drill during itsrotation as affected by the substance which it encounters duringdrilling, and visual indicating means connected to said electrical meansand visually indicating the resistance encountered by each drill at eachposition of its rotary movement along with rotation of said holder, anelongated driving shaft for said holder,

said holder being a disc secured to the front end of said driving shaftfor positioning said front end in a location to drill forwardly, meansto rotate said shaft, said electrical means including a plurality ofcurrent collectors spaced along the axis of said shaft of a numbercorrespending in number to the number of said rotary drills and eachcollector being connected to an associated one of said drills, amplifiermeans connected to said collectors for amplifying the signal produced bysaid electrical means, said amplifier means being connected to saidvisual indicating means for amplifying an electrical visual indicationof the variations in resistance encountered by said rotary drills.

10. A drilling device comprising a rotary drill holder, a plurality ofdrills rotatably mounted on said holder at a plurality of angularlyspaced locations, means to rotate said drills, electrical meansconnected to each of said drills transmitting an electrical signalvarying in intensity in proportion to the intensity of the resistanceencountered by the associated drill during its rotation as affected bythe substance which is encountered during drilling, and visualindicating means connected to said electrical means to indicate visuallyvariations in resistance encountered by each drill at each location ofits movement during rotation of said rotary drill holder, said rotarydrill holder comprising a relatively large disc positioned in theforward end of an excavation being drilled, an elongated shaft extendingsubstantially axially through the excavation being drilled and connectedat its forward end to said rotary drill holder, means to rotate saidshaft, an end plate spaced from said rotary drill holder and definingbetween said rotary drill holder and said end plate a pressure chamber,an operators station located out of said pressure chamber, a pluralityof electrical collectors spaced along said shaft on the exterior of saidpressure chamber, means connecting said electrical means to saidcollectors, amplifier means connected to said collectors for amplifyingthe signal directed to said collectors by said electrical means, saidvisual indicating means comprising a rotary disc, drive means connectingsaid rotary disc to said shaft for rotating said disc in proportion tothe speed of rotation of said holder, a plurality of lights on said discof a number and location corresponding to the number and location ofsaid drills on said holders, said lights each being connected throughsaid amplifying means to respective collectors connected to respectiveones of said drills, and a fluorescent screen spaced from said disc in aposition to be influenced by the variations in light on the light bulbsheld by said disc and being located adjacent said operators station forproviding a visual indication of the variations in resistance encountered by the drills during their rotary movement along with such holder.

References Cited UNITED STATES PATENTS 1,859,814 5/1932 Wyckotf 73-436 X2,620,386 12/1952 Alspaugh et al. 17550 X 2,752,591 6/1956 Felbeck etal. 17550 X 2,790,968 4/1957 Cook et al. 17550 X 2,826,402 3/1958Alspaugh et al 2991 2,959,405 11/1960 Felbeck 299-1 3,195,661 7/1965Jackson et al. 17595 OTHER REFERENCES Oberg, Erik et al.: MachinerysHandbook, 15th Ed, N.Y., Industrial Press, 1957, page 1835.

CHARLES E. OCONNELL, Primary Examiner.

I. A. CALVERT, Assistant Examiner.

1. A DRILLING DEVICE COMPRISING A ROTARY DRILL HOLDER, MEANS FORROTATING SAID DRILL HOLDER, A PLURALITY OF ROTARY DRILLS MOUNTED FORROTATION ON SAID DRILL HOLDER AT A PLURALITY OF ANGULARLY SPACEDLOCATIONS, MEANS TO ROTATE SAID DRILLS, ELECTRICAL MEANS CONNECTED TOEACH OF SAID DRILLS TRANSMITTING AN ELECTRICAL SIGNAL VARYING ININTENSITY ONLY IN PROPORTION TO THE INTENSITY OF THE RESISTANCE TOROTATION ENCOUNTERED BY THE ASSOCIATED DRILL DURING ITS ROTATION ASAFFECTED BY THE SUBSTANCE WHICH IT ENCOUNTERS DURING DRILLING, ANDVISUAL INDICATING MEANS CONNECTED TO SAID ELECTRICAL MEANS AND VISUALLYINDICATING THE RESISTANCE ENCOUNTERED BY EACH DRILL AT EACH POSITION OFITS ROTARY MOVEMENT ALONG WITH ROTATION OF SAID HOLDER.